Understanding Autism

Understanding Autism

Goodwin and Picard are building devices that measure reliable indicators of nervous-system arousal, such as temperature and sweating. The latest prototype is a sweatband with two electrodes that touch the inside of the wrist. A mild electric current, imperceptible to the wearer, runs between the electrodes, traveling across the skin. When skin becomes sweaty, it conducts electricity better, and the resulting voltage change can be measured and wirelessly transmitted to a laptop computer, PDA, or mobile phone.

Eventually, Goodwin hopes to build a wearable indicator such as a pin that would change color in response to those measurements, revealing whether a child is over- or understimulated. Teachers and parents would then know whether the child needed to be soothed (offering a cold drink of water is one approach) or stimulated by an energetic activity. The device could also help children learn to recognize their own emotions.

Understanding others

The Simons Initiative, funded by Jim Simons ‘58 and Marilyn Simons, supports about a dozen projects at the Institute. “There are very few basic science departments with as many people focused on autism as there are at MIT,” says John Gabrieli, whose work involves imaging the brains of autistic patients as they perform tasks. “Autism is such a pervasive development disorder. You can go at it in a lot of different ways.”

Gabrieli and MIT neuroscientist Rebecca Saxe, PhD ‘03, are studying a particular cognitive skill: the ability to make inferences about other people’s state of mind. In most children, “theory of mind” develops around the age of four, but autistic children usually have significant trouble interpreting other people’s mental states.

Gabrieli and Saxe have demonstrated this in a study of teenagers with and without Asperger syndrome, a disorder on the mild end of the autism spectrum. (Children with severe autism generally can’t handle the MRI process, which involves lying still in a large tube for the duration of the scan.) The researchers concocted moral scenarios and asked the subjects to judge the characters involved. In one, person A passes person B some sugar, and B puts it in his coffee. It turns out there is arsenic in the sugar bowl, and B dies.

Everyone confronted with this scenario agrees that if A knew about the arsenic in the sugar bowl, he has done something morally wrong. If A unknowingly passed the arsenic, however, control subjects do not say A acted immorally, but Asperger patients do.

“For most people, intentions are more important than the outcome,” says Gabrieli. But Asperger patients seem to have difficulty separating the two. He and Saxe are using functional magnetic resonance imaging to search for the neural basis of that impairment. (See technologyreview.com/asperger for some sample images.) In previous studies, Saxe has shown that theory of mind appears to be seated in a brain region called the temporoparietal junction.

MIT neuroscientist Tomaso Poggio, meanwhile, is pursuing a new way to classify autism symptoms: he’s programming computer vision systems that can analyze behavior, helping to refine diagnoses and potentially allowing doctors to tailor future drug treatments to patients. Poggio, a computational neuroscientist, says better diagnostics are needed because autism takes a different form in each child. “With mental diseases, diagnoses are very qualitative and not very clear,” he says.

Poggio’s lab has developed a system that records and quantitatively analyzes behaviors in mice, but adapting it to human behavior is likely to take several years. With such a system, researchers could gather data from a large number of patients and correlate differences in speech patterns, motor coördination, eye movements, and reaction times with specific genetic mutations.

It may seem like a huge undertaking, but such efforts are essential to solving the puzzle of autism, says Poggio, who compares autism research to the “war on cancer” that President Richard Nixon declared in 1971.

“At first, people thought in a few years it would be solved. It turned out to be much more complicated,” he says. “But in the process, a lot has been learned, not only about cancer but also about molecular biology in general.” The attempt to unravel autism could be similar, he says: “I believe the problem can be solved at least to some extent, so I think we have to try.”